1. Field of the Invention
The present invention is directed to a method for manufacturing a metal composite component for an electromagnetic valve.
2. Description of the Related Art
FIG. 1 shows a known fuel injector from the related art having a traditional three-part design of an inner metallic flow guide part and housing component at the same time. This inner valve tube is formed from an inlet connection forming an internal pole, a nonmagnetic intermediate part and a valve seat carrier accommodating a valve seat and is explained in greater detail in the description of FIG. 1.
Published German patent application document DE 35 02 287 A1 has already described a method for manufacturing a hollow cylindrical metal housing having two magnetizable housing parts and a nonmagnetic housing zone between them, magnetically separating the housing parts. This metal housing is premachined from a magnetizable blank in one piece down to an excess in the outside diameter, a ring groove being cut in the inside wall of the housing in the width of the intended central housing zone. With a rotating housing, a nonmagnetizable filler material is packed into the ring groove under heating of the ring groove area while maintaining the rotation of the housing until the filler material solidifies. Next the housing is reworked on the outside to the final dimension of the outside diameter, so there is no longer a connection between the magnetizable housing parts. A valve housing manufactured in this way may be used in the solenoid valves for anti-lock brake systems (ABS) in motor vehicles, for example.
In addition, published German patent application document DE 42 37 405 C2 describes a method for manufacturing a solid core for injectors for internal combustion engines (FIG. 5 of the document). These methods are characterized in that a one-piece sleeve-shaped magnetic martensitic workpiece is provided directly or via prior conversion processes, undergoing a local heat treatment in a central section of the magnetic martensitic workpiece to convert this central section into a nonmagnetic austenitic central section. Alternatively, in the local heat treatment by laser, molten austenite or molten ferrite-forming elements are added at the site of the heat treatment to form a nonmagnetic austenitic central section of the solid core.